OS reinstallation

McAfee in my opinion is junk and I would recommend using Microsoft Security Essentials instead of it. However if you really want McAfee and other preinstalled software you should be able to get it from My Dell Downloads:

https://smartsource.dell.com/Web/Welcome.aspx?ReturnUrl=%2fweb%2fmain.aspx 

My Dell Downloads only works in 32 Bit Internet Explorer and even then it sometimes has difficulties registering the system.

The factory settings and partition in general can't be used once the unit has had an OS manually installed.

Sounds like the service guy had no clue what he was doing, I would also be cautious whether your Windows 7 Ultimate is genuine... If it is genuine you can obtain the product key with Belarc Advisor.

Your actual Home Premium License will be on a COA underneath the battery. You may download a Windows 7 Home Premium .iso and use this to clean install:

http://philipyip.wordpress.com/windows-7-sp1-iso-download/ 

For more details you may see Windows Reinstallation Guide/A Clean install of Windows 7:

http://philipyip.wordpress.com/dell-community-forums/ 

This will give you detailed instructions on the clean install, including drivers and preinstalled software and a means of making a backup once the clean install has taken place.

Thanks for your reply

It is true that it is very difficult to get  pre installed software downloads from DELL site. DELL tech support is also very poor. I could not reach them through Call center number. My Warranty period is still live and the retailer from whom i bought my laptop could not help on this and he is diverting to dell service center.

My OS was Windows 7 Home Basic. With the serial key can i re install my OS?   I got my serial key as you mentioned it was underneath the battery.

where can i download Win 7 Home basic and do clean install.

Thnx in advance